首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Three isomeric metal-organic frameworks,[Cd2(X)(btc)(DMA)3]n(X = Cl(1),Br(2),I(3),H3btc =1,3,5-benzenetricarboxylic acid and DMA = N,Nˊ-dimethylacetamide),have been synthesized and characterized by elemental analysis,infrared spectra(IR),thermogravimetric(TG) analyses and single-crystal X-ray diffraction.Single-crystal X-ray analysis reveals that compounds 1–3 crystallize in the orthorhombic P212121 space group,and feature a three-dimensional(3D) extended framework containing dinuclear [Cd2(COO)3] units as the secondary building units(SBUs).Topological analysis reveals that compounds 1–3 can be simplified into a 3-connected srs topological network.  相似文献   

2.
A novel compound of 1,2-dis(1,3-diphenylpropan-2-yl)disulfane(C30H30S2,Mr=454.27)was synthesized in ethanol with 1,3-diphenyl-2-propanone as raw materials,giving high yield of product(90%).Its structure was determined by IR,1H NMR,MS,elemental analysis and X-ray diffraction.The crystal belongs to monoclinic,space group C2 with a=18.727(3),b=6.5179(9),c=13.7576(18),β=131.0610(10)o,V=1266.2(3)3,Z=2,Dc=2.136 g/cm3,μ=1.078 mm-1,F(000)=843,R=0.0490 and wR=0.1247 for 3211 observed reflections with I>2(I).X-ray analysis reveals that the molecule is not symmetrical.There exist no classical hydrogen bonds andπ-πstacking interactions.Moreover,the thermal stability of compound 3 was investigated.  相似文献   

3.
Two new coordination polymers,[Zn(bdc)(1,3-bimb)]n(1) and {[Mn2(ox)2(1,3,5tib)4/3]·4H2O}n(2)(H2ox = oxalic acid,H2bdc = terephthalic acid,1,3-bimb = 1,3-bis(imidazol-1ylmethyl)benzene,1,3,5-tib = 1,3,5-tri(imidazol-1-yl)benzene),were synthesized and characterized by elemental analysis,IR,powder X-ray diffraction(PXRD),and thermogravimetric(TG) analyses.X-ray diffracation analysis reveals that two kinds of zigzag chains [Zn(bdc)]n and [Zn(1,3-bimb)]n in compound 1 are interweaved to form a 3D 4-fold interpenetrated 66-dia framework.In compound 2,Mn(1) and Mn(2) are linked via 1,3,5-tib ligands to form two different nets of [Mn6(1,3,5-tib)6 ]n along the ab plane with inner-or outer-shape N–Mn–N angles,which are connected by 1D infinite [Mn2(ox)2 ]n chains via Mn–O bonds to result in a(3,3,3,4,4)-connected(4·8·10)3(4·82)3(4·83·102)6(82·104·3)3(83)4 topology.Moreover,the photoluminescence of 1 has been investigated.The crystal of 1 crystallizes in orthorhombic,space group Pna2 with a = 13.2267(6),b = 9.1717(4),c = 17.4492(8),V = 2116.79(16)3,Z = 4,C22 H18N4O4 Zn,Mr = 467.77,Dc = 1.468 g/cm3,F(000) = 960 and μ(MoKα) = 1.197 mm-1.The final R = 0.0280 and wR = 0.0618 for 3695 observed reflections with I 2(I) and R = 0.0389 and wR = 0.0653 for all data.The crystal of 2 crystallizes in rhombohedral,space group R-3 with a = 22.080(8),c = 31.19(2),V = 13167(11) 3,Z = 18,C24 H25 Mn2 N8 O13,Mr = 743.40,Dc = 1.688 g/cm3,F(000) = 6822 and μ(MoKα) = 0.945 mm-1.The final R = 0.0429 and wR = 0.1035 for 5160 observed reflections with I 2(I) and R = 0.0824 and wR = 0.1244 for all data.  相似文献   

4.
丁慧文  钟家亮  杨萍  穆青 《结构化学》2013,(9):1303-1306
A highly hydrophobic cyclic peptide GG-110824,cyclo(Gly-Leu-Val-Leu-LeuVal-Pro-Ile-Gly-Leu)(C49H86N10O10),has been synthesized by a strategy combined with solid-phase synthesis(SPPS) of linear peptide and cyclization in solution.The structure including the absolute configuration of synthesized GG-110824 was confirmed by CuK radiation X-ray crystallography in the monoclinic system,space group P21 with a = 11.4966(10),b = 18.5286(2),c = 13.3943(10),= 95.03o,V = 2842.20(4)3,F(000) = 1080 and Z = 2.  相似文献   

5.
An aromatic azo-polymer, poly(thiourea-azo-sulfone)(PTAS), has been prepared using 4-(4-aminophenylsulfonyl)benzenamine and diazonium salt solution of 2,6-diaminopyridine. PTAS was easily processable using polar solvents and had high molar mass 63 × 103g mol 1according to GPC. Mechanically and thermally stable and electrically conducting polymer/CNTs nano-composites were obtained via melt processing technique. Fine distribution of CNTs in a polymer matrix performed an essential role in the preparation of polymer/CNTs nano-composites based on interfacial interaction between CNTs and polymer matrix. Scanning electron micrographs showed good dispersion of filler and adhesion of matrix on the surface of nanotubes. Accordingly, increasing the amount of CNTs from 0.1 wt% to 5 wt% increased the electrical conductivity from 2.99 S cm 1to 3.56 S cm 1. Mechanical strength of functional nanotubes-based hybrids was enhanced from 43.22 MPa to 65.02 MPa compared with that of hybrids with non-functional filler in matrix 37.21 MPa. A rapport between nanotube loading and thermal stability of the materials was also observed. 10% gravimetric loss temperature was increased from 528 °C to 578 °C, while glass transition was improved from 241 °C to 271 °C. Adding up of small quantity of functional CNTs strongly affected the tensile, electrical and thermal properties of materials. Improvement of the physical properties of CNT-reinforced polymer nano-composites was ascribed to the melt processing technique.  相似文献   

6.
梁碧玲  程度 《高分子科学》2014,32(3):321-332
Antibody targeted delivery is an effective strategy to improve the diagnostic imaging outcome of nanoscale imaging agents in the focal areas.Dual targeting micelles encapsulating superparamagnetic iron oxide were prepared from the amphiphilic block copolymer poly(ethylene glycol)-poly(ε-caprolactone)(PEG-b-PCL) with different targeting ligands cRGD and scFv-ErbB single chain antibody conjugated to the distal ends of PEG block.The breast cancer animal model was established by subcutaneous injecting the BT474 cells into the BALB/c-nu female nude mice and then employed to assess the potential of the dual ligand targeted magnetic micelles as a novel MRI contrast agent on a 1.5 T clinical MRI scanner.The T2 signal intensity of the tumor in animals receiving the dual ligand targeted magnetic micelles via tail vein decreased more significantly than the single ligand targeted and nontargeted magnetic micelles.These results indicate that the dual ligand targeted magnetic micelles,cRGD/scFv-ErbB-PEG-PCL-SPION,have great potential to act as a new type of effective nanoscale MRI contrast agent for early diagnosis of breast cancer.  相似文献   

7.
Theoretical calculations were carried out to predict the aqueous-phase acidities of a series of drug 1-phenyl-4-propylpiperazine and its derivatives. The performances of the density functional theory(DFT) methods B3LYP and B3P86, solvation models[the polarized continuum model(PCM) and the conductor-like polarized conti- nuum model(CPCM)], and the basis set effect were tested. A comparison between the theoretical and experimental pKa values for para-substituted 1-phenyl-4-propylpiperazines reveals that the accuracy of B3LYP is better than that of B3P86, and the basis set 6-31++G(d,p) and the CPCM model are suitable for calculating pKa values of the substituted 1-phenyl-4-propylpiperazine. For the investigated compounds, a reasonable agreement between the experimental and calculated oKo values was also observed.  相似文献   

8.
Carbazole-based bi-functional photorefractive polyacrylates were prepared via free radical polymerization and post-azo-coupling reaction. The structure of polymers was characterized by Fourier transform infrared spectroscopy(FTIR) and proton nuclear magnetic resonance(1H-NMR) spectroscopy. The differential scanning calorimetry(DSC) and the thermal gravimetric analysis(TGA) were used to characterize the thermal property of polymers. The results indicate that though the glass transition temperature(Tg) of polymers increases with increasing the ratio of NLO groups, the polymers with different ratios of NLO groups still all show low glass transition temperatures around 60 °C, and good thermal stability, which are favorable to the practical application of these polymers. The gel permeation chromatographic(GPC) result indicates that these polymers all have high-molecular-weight which is favorable to the long term stability of the material. Further, these polymers have good solubility in chloroform solvent, and the solutions can easily be fabricated into optically transparent films. Gain coefficients of 75 cm-1, 185 cm-1 and 66 cm-1 can be observed at zero external electric field without any addition agent or pre-poling for polymers P-2, P-3 and P-4 respectively. The different contents of NLO groups result in the different properties of polymers P-2, P-3 and P-4.  相似文献   

9.
Nanocomposites of polyaniline(PANI) and the macrocycle thiacalix[4]arene tetra sulfonate(TCAS) were successfully synthesized in feed ratios of 1:0.25, 1:0.50 and 1:0.75 by three prevail synthetic methods, i.e. in situ polymerization, emulsion polymerization and solution casting technique. The structures of the nanocomposites were confirmed by FTIR, UV-Vis, XRD, SEM, and TEM techniques. The conductivity was measured by a four probe method. The conductivity was recorded to be as high as 105 × 10 2S cm 1for the nanocomposite with a nanometer size structure and homogeneously distributed morphology. The electroactivity of the nanocomposites was approved by cyclic voltammetry(CV) and impedance spectroscopy technique(EIS). The antioxidant ability and thermal property of the composites were further studied. Preliminary studies have evidenced the production of conductive nanocomposites with good thermal property and relatively good solubility in N-methyl 2-pyrrolidone(NMP), with the antioxidant activity reaching up to 80%.  相似文献   

10.
王宗宝  顾群 《高分子科学》2013,31(12):1717-1724
Lamellar crystals of diblock, triblock and four-arm poly(ethylene glycol)-b-poly(ε-caprolactone) (PEG-b-PCL) crystalline-crystalline copolymers were successfully obtained from their solution. Morphology and structure of lamellar crystals of crystalline-crystalline copotymers were investigated using tapping-mode atomic force microscopy (AFM) and selected area electron diffraction (SAED). All of these samples showed the truncated-lozenge multilayer basal shapes with central screw dislocation or central stack, which were all obtained simultaneously from the oil bath. The diffraction pattern of PEG block lamellar crystal is attributed to the (120) diffracting planes and the pattern of PCL block lamellar crystal is attributed to the (1 I0) diffracting planes and (200) diffracting planes according to the SAED results. Four (110) crystal growth planes and two (200) crystal growth planes are discovered for the PCL blocks, but the (120) crystal growth planes of PEG blocks are hided in the figure of AFM. The crystalline structure of the four-arm copolymers (FA) is more disorder and confused than that of the diblock (DI) copolymer and the striated fold surface structures of lamellar crystals of four-arm copolymers (FA) are smoother than these of linear analogues, owing to the confused crystallization of blocks caused by the mutual restriction of blocks and the hindrance of the dendritic cores. In addition, the aspect ratio of FA is greater than that of the others. It is hypothesized that there are two reasons for the change of aspect ratios. First, the (200) diffracting planes of PCL crystals grew slowly compared to their (110) diffracting planes because of difference in the energy barrier. Secondly, edge dislocations on the (200) diffracting planes are also responsible for the variation of the aspect ratio. Consequently, the crystalline defects are augmented by the competing blocks crystallized simultaneously and the hindrance of the dendritic cores.  相似文献   

11.
袁金颖 《高分子科学》2014,32(6):690-702
In this work, a UV-Visible light controlled supramolecular system based on ethyl cellulose(EC) was constructed, combining the host-guest interaction of β-cyclodextrin(β-CD) group and trans-isomer of azobenzene(tAzo) group. To link β-CD to the hydrophobic section, renewable EC was used as macroinitiator to initiate the polymerization of ε-caprolactone(ε-CL) to form biocompatible and biodegradable comb copolymer EC-g-PCL, and β-CD was attached to the end of PCL side chain via click reaction. Meanwhile, hydrophilic PEG-tAzo was obtained by N,N'-dicyclohexylcarbodiimide(DCC) coupling. Then, the structures of the products were characterized by nuclear magnetic resonance(NMR) and gel permeation chromatography(GPC). Subsequently, with the formation of inclusion complexes by β-CD and tAzo groups, the obtained EC-g-PCL-β-CD/PEG-tAzo supramolecular system self-assembled in water with hydrophobic EC-g-PCL-β-CD as core and hydrophilic PEG-tAzo as shell. Furthermore, dynamic light scattering(DLS) and transmission electron microscopy(TEM) were utilized to investigate the particle size and size distribution, while NMR and UV-Vis spectra were applied to explore the UV-Visible light stimuli-responsiveness of the micelles.  相似文献   

12.
Ultrathin MoS2nanosheets were prepared in high yield using a facile and effective hydrothermal intercalation and exfoliation route. The products were characterized in detail using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The results show that the high yield of MoS2nanosheets with good quality was successfully achieved and the dimensions of the immense nanosheets reached 1 μm–2 μm. As anode material for Li-ion batteries, the as-prepared MoS2nanosheets electrodes exhibited a good initial capacity of 1190 mAh g-1and excellent cyclic stability at constant current density of 50 mA g-1. After 50 cycles, it still delivered reversibly sustained high capacities of 750 mAh g-1.  相似文献   

13.
Dye sensitized solar cell(DSSC) is a promising thin film solar cell that has been widely investigated after its birth because of its advantages,such as flexibility,low-cost,easyfabrication and so on[1-3].For DSSCs,sensitizers play a core role due to their responsibility for the generation of the photo carriers resulted from light absorption and the transfer of the photo-generated electrons into semiconductor photoanodes[4].Keywords:Light-harvesting complex Ⅱ; Anthraquinone 2-carboxylic acid; ZnO; TiO2 nanostructure; Solar cell  相似文献   

14.
侯向阳  王潇  付峰  王记江 《结构化学》2013,(9):1339-1347
Two new PbII metal-organic coordination polymers,namely,[Pb(tda)]n(1) and [Pb(tda)(phen)]n(2)(H2 tda = thiodiglycolic acid,phen = 1,10-phenanthroline),were synthesized under hydrothermal conditions and characterized by elemental analysis,IR,UV spectra,TG technique and X-ray crystallography.Complex 1 crystallizes in the orthorhombic system,space group Iba2 with a = 9.0417(14),b = 19.360(4),c = 7.5741(12),C4H4O4PbS,Mr = 355.32,V = 1325.8(4)3,Dc = 3.560 g·cm-3,F(000) = 1264,μ(MoKa) = 25.711 mm-1,S = 1.086 and Z = 8.The final refinement gave R = 0.0387 and wR = 0.0986 for 3077 observed reflections with I > 2σ(I).Complex 1 is a 2D infinite grid-like(4,4) topological structure constructed by PbII atoms and tda anions,in which tda ligands exhibit bis(syn,syn-bridging bidentate,chelating-bridging tetradentate) mode.Complex 2 crystallizes in the triclinic system,space group P1 with a = 8.3570(17),b = 8.7591(18),c = 10.895(2),α = 76.00(3),β = 80.50(3),γ = 77.61(3)°,C16H12N O4PbS,Mr = 535.53,V = 750.4(3)3,Dc = 2.370 g·cm-3,F(000) = 504,μ(MoKa) = 11.405 mm-1,S = 1.018 and Z = 2.The final refinement gave R = 0.0332 and wR = 0.0629 for 3360 observed reflections with I > 2σ(I).Complex 2 is a 1D chain structure,in which phen ligands are attached on both sides of the 1D chain and tda ligand exhibits a bis(syn,syn-bridging bidentate,chelating tridentate) mode.Finally,complex 2 is extended into a 2D supramolecular structure by strong π···π stacking interactions.  相似文献   

15.
A facile method was succcssfidly developed to prepare a "pine needle-like" nanocompositc of carbon nanotubcs/polylhiophenc(CNTs/PTh) in ethanol with the assistance of supercritical CO2(SC CO2). The experiment conditions such as mass ratio of thiophene monomer to carbon nanotubes, reaction temperature, and reaction time wcrc optimized, and the morphology and thickness of PTh layers on CNTs were hence effectively controlled. The results of Fourier translbrm infrared(FTIR) spectra, X-ray photoelectron spectra(XPS) and Raman spectra indicate the π-π interactions between PTh and CNT. A possible formation mechanism about the unique microstructure was suggested by virtue of the morphological evolution of the nanocomposite. As a facile, environment benign, and adjustable method, the proposed method holds great potential in the preparation of functional hybrid nanocomposites with the help of SC CO2, which will be promising in the tields of nanofabrication and electrochemical device preparation.  相似文献   

16.
A cocrystal based on 1,3-di(4-pyridyl)propane and 3-((4′-carboxybenzyl)oxy)benzoic acid,C13H14N2·C15H12O5,has been synthesized and characterized by single-crystal X-ray diffraction.The compound crystallizes in monoclinic,space group P21 /c with a = 11.639(4),b = 9.808(3),c = 20.854(6),β = 91.242(7)°,V = 2380.0(13)3,C28H26N2O5,Mr = 470.51,Dc = 1.313 g/cm3,μ(MoKα) = 0.091 mm-1,F(000) = 992,Z = 4,the final R = 0.0677 and wR = 0.1477 for 4175 observed reflections(I > 2σ(I)).Intermolecular N H···O hydrogen bonds link two kinds of components into a one-dimensional chain in [10-1] direction and adjacent chains are further arranged into a two-dimensional network by π···π and C H···π interactions.Investigation of intermolecular interactions and crystal packing via Hirshfeld surface analysis reveals that the close contacts are mainly focused on weak interactions.The theoretical investigations with HF/6-31G(d) method were performed,and its stability,frontier molecular orbital composition and Mulliken charge distribution were also discussed.  相似文献   

17.
黄伟  佘能芳 《结构化学》2013,(9):1357-1361
The crystal structure of the new title compound 2,2-dimethyl-4-oxochroman-3-ylmorpholine-4-carbodithioate(C16H19NO3S2,Mr = 337.44) has been prepared and determined by single-crystal X-ray diffraction.The crystal is of triclinic,space group P1 with a = 9.5518(7),b = 9.7172(7),c = 11.0220(8),α = 67.08(1),β = 74.66(1),= 61.31(1)°,V = 822.72(10)3,Z = 2,Dc = 1.362 g/cm3,F(000) = 356,μ = 0.092 mm-1,MoKa radiation(λ = 0.71073),R = 0.0515 and wR = 0.1389 for 2623 observed reflections with I > 2(I).X-ray diffraction analysis reveals that the chroman ring adopts a half-chair conformation while the morpholine ring shows a chair conformation.Intramolecular and intermolecular C-H···S and C-H···O hydrogen bonds together with π-π interations are found in the structure.The result of MTT assay shows the title compound displays good antiproliferative activity against two human cancer cell lines.  相似文献   

18.
钟鸿  郭小芳  王瑞虎 《结构化学》2013,(9):1325-1333
Three Cd(II) coordination complexes,{[Cd(bime)3](NO3)2·(H2O)3}n(1),[Cd(bime)Br2]n(2) and [(H2bime)(CdBr4)(H2O)]n(3)(bime = 1,2-bis(imidazol-1-yl)ethane),have been prepared and characterized.Single-crystal X-ray diffraction analysis reveals that 1~3 crystallize in the trigonal space group P-3,monoclinic space group C2/c and triclinic space group P1,respectively.In 1,bime bridges six-coordinated Cd(II) to generate a two-fold interpenetrating 3D coordination polymer,in which NO3- is not involved in coordination,but serves as a void filler to balance the charge of the 3D framework.The six NO3- and six uncoordinated water molecules form an unprecedented 24-membered macrocycle through hydrogen bonding interaction.In 2,bime in an anti-conformation links the CdBr2 units into a zigzag chain.In 3,bime does not take part in coordination,but is protonated to act as a counter cation of [CdBr4 ]2-.The hydrogen bonds between H2bime and [CdBr4]2- result in the formation of a supramolecular chain.  相似文献   

19.
李正义  来源  石嵩  韩辰  陈亮  孙小强 《结构化学》2013,(9):1387-1391
The title compound 5,17-diformyl-11,23-di(tert-butyl)-25,26,27,28-tetrapropoxycalix[4]arene has been synthesized by selective formylation of 5,11,17,23-tetra(tert-butyl)25,26,27,28-tetrahydroxycalix[4]arene in three steps and characterized by1H NMR and X-ray single-crystal diffraction.The crystal belongs to the monoclinic system,space group C2/c with a = 25.760(3),b = 10.9952(10),c = 18.630(2),β = 119.985(4)°,V = 4570.4(9)3,Z = 4,Dc = 1.106 g/cm3,Mr = 761.01,F(000) = 1648,μ = 0.071 mm-1,MoKa radiation(λ = 0.71073),R = 0.0710 and wR = 0.2411 for 3234 observed reflections with I 2σ(I).X-ray analysis reveals that the title compound adopts a pinched cone conformation which leads to an open cavity.Intermolecular C–H O weak interactions link the molecules along the bc plane,which are effective in the stabilization of the crystal structure.  相似文献   

20.
Crosslinked x-P(St-MAA) seed latex was first prepared via soap-free emulsion copolymerization of styrene (St) and methyl methacrylic acid (MAA) with divinyl benzene as crosslinker and ammonium persulfate as initiator, and x-P(St-MAA)/x-P(St-NaSS) core/shell latex particles were then synthesized through a novel seeded emulsion copolymerization of St and sodium styrene sulphonate (NaSS) in the presence of water-soluble crosslinker N,N'-methylene bisacrylamide (BAA) using oil-soluble 2,2-azobis isobutyronitrile as initiator. TEM observation indicated that narrow dispersed core/shell latex particles were obtained, and element analysis showed that NaSS unit content in the whole particle and in the shell reached 22.8 wt% and 51.2 wt%, respectively.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号